1. Field of the Invention
The present invention relates to a feeder for feeding electronic chip components, and more specifically to a feeder for feeding a plurality of randomly oriented electronic chip components in an aligned state.
2. Description of the Related Art
In order to feed electronic chip components such as capacitors, resistors, transistors, and filters, a plurality of randomly oriented electronic chip components are dispensed in an aligned state one by one by a feeder.
FIG. 6 schematically illustrates a related feeder 1 for electronic chip components. The feeder 1 for feeding electronic chip components includes a pooling section 2, an aligning section 3, a conveying section 4, and a dispensing section 5, as respective functional sections.
The pooling section 2 is formed of a hopper 7 for pooling a plurality of randomly oriented electronic chip components 6 (shown in aggregation). A discharge opening 8 is formed in the bottom portion of the hopper 7. The above-mentioned aligning section 3 is arranged in association with this discharge opening 8.
FIG. 7 is a perspective cut-away view illustrating the aligning section 3. As indicated there, an aligning path forming member 10 is formed in the aligning section 3, forming a tubular aligning path 9. The aligning path forming member 10 is placed inside of the discharge opening 8. The aligning path forming member 10 reciprocates in the axis direction of the discharge opening 8 as shown by a predetermined stroke range 11. This movement is provided by a driving mechanism 30. The broken line indicates an upper bound of the stroke range 11. Because of this movement, the aligning path forming member 10 acts on electronic chip components 6, which are to be discharged from the discharge opening 8, so as to agitate them. Only the electronic chip components 6 which have become oriented in the predetermined aligning direction by this agitation pass into the tubular aligning path 9.
In the aligning section 3 shown in FIG. 7, in order to enable electronic chip components 6 of small size to be fed, a fixed pipe 12 for guiding electronic chip components 6 in an aligned state is further formed within the tubular aligning path 9 of the aligning path forming member 10. The inner diameter of the fixed pipe 12 is selected so as to be able to receive an electronic chip component 6 only when the longitudinal direction of the electronic chip component 6 substantially agrees with the axis direction of the fixed pipe 12.
In this manner, the aligning path forming member 10 agitates electronic chip components 6, which are to be discharged from the discharge opening 8, by its reciprocating movement so as to smoothly move electronic components 6 in the hopper 7 and to guide them to the aligning path 9 or the fixed pipe 12 as well. In order to more smoothly guide electronic chip components 6 to the aligning path 9 or the fixed pipe 12, an inverse conical-shaped concave surface is formed on an end face 13, located within the hopper 7, of the aligning path forming member 10.
Referring again to FIG. 6, the electronic chip components 6 passed through the aligning path forming member 10, or more specifically, through the fixed pipe 12, will advance to the conveying section 4. In the conveying section 4, a conveying path 14 such as a conveyor belt (not shown) is formed. The conveying path 14 is used for conveying the electronic chip components 6 passed through the fixed pipe 12 in an aligned state.
At the end of the conveying path 14, the above-mentioned dispensing section 5 is formed. In the dispensing section 5, a dispensing mechanism (not shown) for dispensing electronic chip components 6 is disposed. A picking-up apparatus for picking up electronic chip components 6 (such as a vacuum chuck) can be used for the dispensing mechanism.
As described above, since the aligning path forming member 10 agitates electronic chip components 6 by its reciprocating movement so as to guide them to the aligning path 9 or the fixed pipe 12, one or more electronic chip components 6 must be ideally guided into the fixed pipe 12 every cycle of the reciprocating movement of the aligning path forming member 10 without any discontinuance.
However, while the aligning path forming member 10 repeats the reciprocating movements, there are some occurrences in which electronic chip components 6 are not guided into the aligning path 9 or the fixed pipe 12. These occurrences are more likely when a comparatively large number of electronic chip components 6 remain in the hopper 7. One reason for these occurrences may be that the agitation movement by the aligning path forming member 10 does not sufficiently act on (e.g., agitate) the electronic chip components 6.
In order to solve the above-mentioned problem, the stroke 11 of the reciprocating movement of the aligning path forming member 10 is increased to obtain harder agitating action. However, when the stroke 11 of the aligning path forming member 10 is increased in this way, the following problems may occur.
First, since an impact on the electronic chip components 6 by the aligning path forming member 10 is increased, electronic chip components 6 may be damaged, reducing the quality of electronic chip components 6.
Next, when a cycle per unit time is maintained while the stroke 11 of the aligning path forming member 10 is increased, it is necessary to increase the driving speed of the aligning path forming member 10. This causes an increase in the load to the mechanism 30 for driving the aligning path forming member 10. This can result in disadvantages such as a breakdown of the mechanism, a reduced life of the mechanism, and/or frequent maintenance of the mechanism.
Also, if the stroke 11 of the aligning path forming member 10 is increased, when a small number of electronic chip components 6 remain in the hopper 7, the electronic chip components 6 "jump" in the hopper 7. This may prevent the components 6 from smoothly entering into the aligning path 9 or the fixed pipe 12.